Corneal sensitivity during the menstrual cycle

Corneal sensitivity was determined in 5 women with regular menstrual cycles by means of a new aesthesiometer developed by Dräger. Throughout one menstrual cycle we measured corneal touch thresholds (CTT) daily and did serial determinations of urinary luteinising hormone and pregnanediol levels. CTT rose in 4 women with proved ovulation in the days before or on the day of ovulation, while corneal sensitivity remained unchanged in one anovulatory subject. We observed no changes in CTT prior to menstruation. The decrease in corneal sensitivity might be related to the preovulatory oestrogen peak.